1. Technical Field
The present invention relates to a vehicle lamp control device. More particularly, the present invention relates to a vehicle lamp control device used in automobiles or the like.
2. Description of the Related Art
Conventionally, there is known an auto-leveling control which automatically adjusts a position of an optical axis of a vehicle headlamp according to an inclination angle of a vehicle and changes an irradiation direction of the headlamp. Generally, in the auto-leveling control, a position of an optical axis of a headlamp is adjusted on the basis of a pitch angle of a vehicle derived from an output value of a vehicle height sensor. On the contrary, JP-A-2012-030782 and JP-A-2012-030783 disclose a vehicle lamp control device in which an auto-leveling control is performed using an inclination sensor such as an acceleration sensor.
In the case of using an inclination sensor such as an acceleration sensor, a gyro sensor (an angular velocity sensor and an angular acceleration sensor) and a geomagnetic sensor, an auto-leveling system can be made in a less expensive manner and it is possible to reduce the weight of the auto-leveling system, as compared with the case of using a vehicle height sensor. As a result, it is possible to reduce the weight and cost of a vehicle. On the other hand, even in the case of using the inclination sensor such as the acceleration sensor, there is a demand to execute the auto-leveling control with high accuracy.
The present inventors have intensively studied in order to achieve the high accuracy of an auto-leveling control. As a result, the present inventors have recognized that there is room for improvements in terms of the higher accuracy of the auto-leveling control in a conventional vehicle lamp control device.